1. Field of the Invention
The present invention relates generally to soil stabilization methods and to compositions for use therein and, specifically to a method for improving the characteristics of sulfate bearing soils by treating with barium compounds in conjunction with lime stabilization.
2. Description of the Prior Art
Pretreating building sites for improving the strength and volume change characteristics of the soil is a long known problem facing the civil and architectural engineer. There are many examples in the prior art of methods and materials used to stabilize soils, or to improve subgrades in the subsurface layers adjacent the surface of the earth for a variety of purposes. Thus, in the past, subgrades have been improved as building sites, streets, runways, railroads, for remedial stabilization of existing structures, slope stabilization and for landfill stabilization, to list several typical examples. Lime and lime slurries have been worked into the top layers of the earth; for example 6 to 36 inches in depth, to improve and stabilize soils or subgrades. Chemical soil stabilization by injection of lime slurry at predetermined depths below the soil surface is also known using slaked or hydrated lime.
Despite these advances in the art, a need continues to exist for a method for improving the characteristics of soils or subgrades, particularly those soils which have a high sulfate content making them subject to undesirable swell or expansion.
A need also exists for such a method which improves the bearing strength values of such soils to thereby build compressive strength in the subsurface layers.
A need exists for such a method which is simple and economical in practice and which is compatible with existing lime stabilization techniques.